Poly(alpha-olefin) (PAOs) fluids are commercially employed as base stocks in lubricant products. PAOs have many advantages compared to conventional mineral oils and Group III/III+ lubricants. More specifically, PAOs have superior VI (viscosity index), low temperature properties (CCS (crankcase simulation), MRV (mini-rotary viscometer), etc.), pour points, and low traction, which translates into better energy efficiency and additive response and complete miscibility in conventional mineral oils. Performance limitations of PAOs include a lack of polarity, which impacts ability to solubilize polar additives, such as antioxidants, anti-rust agents and anti-wear agents. Conventionally, polar organic esters have been added to PAO lubricants to render them compatible. Useful commercial formulations may have 2% or more of such esters in a fully homogeneous lubricant blend. Examples of such esters include, for example, bis-tridecanol adipate and pentaerythritol hexanoate.
Polyalkylene glycol (PAG) fluids have also been employed as lubricant base stocks. Their performance advantages are high VI, good lubricity (in hydrodynamic, mix, and boundary lubrication conditions), and excellent cleanliness. Some grades are even considered acceptable for incidental food contact (H1 grade). Performance limitations include lack of miscibility and compatibility with conventional mineral and hydrocarbon-based lubricants as well as high solubility in water, which results in severe corrosion problem. Some PAGs have paint or seal compatibility problems. The formulation or additive response of PAGs with respect to additives can be unpredictable, rendering them difficult to formulate with.
Other teachings to useful PAO and PAG fluids and processes for making are disclosed in Synthetics, Mineral Oils, and Bio-Based Lubricants, Chemistry and Technology, by L. R. Rudnick, CRC Press, © 2006.
It would be desirable to have a process for making poly(alkyl epoxides) that is economical and easy to control. It would further be desirable to have a process for making poly(alkyl epoxides) in which mixtures of α-olefins could be utilized for epoxidation and oligomerization. It would also be desirable to have a process for making poly(alkyl epoxides) employing an initiator for polymerization. It would also be desirable to have poly(alkyl epoxides) that are highly soluble in PAO-type hydrocarbon fluids and that have a base stock that exhibits a low coefficient of friction. It would also be desirable to have a lubricant composition having a base stock of a poly(alkyl epoxide).